Al-Fath 48:28

The Prophet Muhammad had to play dual roles: one was that of a prophet (who strives to spread the message of God) and the other was that of the final Prophet, i.e. no other prophet was to appear after him. In his former capacity he had to do the same work as other prophets, namely to declare the oneness of God, to warn and to give good news about the Hereafter. The latter role was different in that it required him to create those historical conditions which would be conducive to and a guarantee of the protection of both the Book of God and the prophetic traditions. No situation should occur which would necessitate the appointment of another prophet. It was thus a requirement of this second role that his dawah work should not end with a simple ‘declaration’ but should reach the stage of ‘revolution’—revolution in the sense that change should be brought about in the history of the world. Those conditions should come to an end under which, time and again, God’s guidance had been obliterated or distorted, thereby necessitating the selection of a new prophet to restore the divine guidance to its original form.